This invention relates to locking cables for bicycles and other portable objects and in particular relates to a flexible locking cable made of a metal reinforcement completely disposed between contiguous ploymeric or elastomeric layers.
With a resurgence in the use of bicycles, motorcycles and similar articles, there has been a concomitant increase in thefts of these articles. A number of different types of locking mechanisms have been utilized in an attempt to discourage such thefts. The most popular locking mechanism consists of a length of chain which is drawn through the spokes of a wheel and around the frame, for instance, and then the ends of the chain entrained around a stationary object (e.g. a bicycle rack) and coupled together with a padlock. The sophisticated thief has no problem rapidly breaking chains of moderate size with the aid of bolt cutters or a hacksaw, even when the individual links are made of hardened steel. Alternatively, by taking advantage of the brittle character of the chain at low temperatures, thieves have been known to apply freon to one of the chain links causing it to become very brittle and permitting the thief to easily shatter the link by imposition of a shock load; this method is successfully applied to fairly heavy duty chains.
While many of these chain-type locks employ a plastic sleeve loosely fitted over the chain to prevent scratching of the bike parts, such plastic sheet or sleeve does not prevent the thief with the aid of freon from embrittling the end most links of the chain coupled with the padlock, combination lock or other locking device and which are outside the plastic sleeve and fully exposed.
Among the objects of the invention are the provision of a locking cable which does not suffer from the drawbacks characteristic of chain-type locks; provision of a flexible metal reinforced polymeric body which is more difficult and takes much more time to sever with bolt cutters, hacksaws, or other customarily used devices; and the provision of a locking cable which is easily and inexpensively manufactured by known techniques and in certain embodiments utilizes heretofor discarded materials.
Briefly described, a flexible locking cable is described comprising a metal reinforcement interposed and sandwiched between an inner elongated flexible heat setting polymeric body and an outer cover composed of a heat setting resilient polymeric material, the reinforcement and outer cover being in intimate engaging contact with one another. The thus formed metal reinforced polymeric cable also has at the ends of such cable means, e.g. integral loops, for receiving a detachable locking device.
The invention also contemplates in one aspect thereof a method for producing a flexible locking cable by using as the inner body thereof a flexible mandrel customarily used in the making of tubular articles such as hose, which mandrel is normally discarded in the making of the hose after a limited period of use. In another embodiment scrap metal-reinforced hose lengths are utilizable as the cable body.